Overactivity of protein kinase C (PKC), an enzyme that is implicated in bipolar disorder and schizophrenia, markedly impairs higher brain functions in animals, according to a Yale study published Oct. 29 in Science.

The research adds to mounting evidence that excessive activity of PKC may underlie the distractibility, impaired judgment, impulsivity, and disturbed thinking seen in bipolar disorder (also known as manic depressive illness), and in schizophrenia.

The study also shows that exposure to mild stress can activate PKC, which may lead to worsening of symptoms in patients with these disorders. The findings may explain how upsetting events in the environment can lead to deterioration in higher brain function, and why patients with schizophrenia or bipolar disorder may be particularly susceptible to stress-induced dysfunction. PKC inhibitors may be useful in treating these illnesses, according to Amy Arnsten, associate professor, Department of Neurobiology at Yale School of Medicine and senior author of the study.

"These new findings may also help us understand the impulsivity and distractibility observed in children with lead poisoning," Arnsten said. "Very low levels of lead can activate PKC, and this may lead to impaired regulation of behavior."

Recent genetic and biochemical studies indicate that bipolar disorder and schizophrenia are associated with overactivity of PKC, and many medications that treat schizophrenia and bipolar disorder reduce PKC activity. However, the link between PKC overactivity and neuropsychiatric symptoms had not been understood.

This study examined the effects of increasing PKC activity in the prefrontal cortex of animals performing working memory tasks. The prefrontal cortex is a brain region that allows for the regulation of thoughts, behaviors and feelings. The prefrontal cortex becomes dysfunctional in both bipolar disorder and schizophrenia. In animals, either direct or indirect activation of PKC dramatically impaired prefrontal cortical function, while inhibition of PKC protected prefrontal function. No changes in performance were seen on cognitive tasks that did not rely on the prefrontal cortex.

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...